Caldwell climate — normals and trends
Caldwell (United States) has a cold semi-arid climate (BSk) under the Köppen-Geiger classification. Its mean annual temperature is 12.2 °C and it receives 285 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is July (26.1 °C on average) and the coldest is January (-0.5 °C). Rainfall peaks in December.
Caldwell averages 89 frost days, 78 hot days (≥ 30 °C) and 68 rainy days per year.
Caldwell has warmed by +1.8 °C between 1940 and 2025, or +0.22 °C per decade. This trend is statistically significant.
The number of frost days there went from about 100 to 78 per year over the period.
The hottest day of the period reached 44.7 °C (on 19 July 1960) and the coldest -30.2 °C (on 22 December 1990).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
CaldwellIdaho
- coords
- 43.66°, -116.69°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
12.2°C
Average daily high
18.6°C
Average daily low
6.2°C
Annual rainfall
285mm
Sunshine / day
10.4h
Mean relative humidity
53%
Average peak wind
14.0km/h
Seasonal range
26.6°C
Frost days (< 0 °C)
89 d/yr
Hot days (≥ 30 °C)
78 d/yr
Rainy days (≥ 1 mm)
68 d/yr
Annual snowfall
30.7 cm
Average feels-like high
16.0 °C
Average feels-like low
3.3 °C
Average peak gust
29.6 km/h
Tropical nights (≥ 20 °C)
12 d/yr
Solar radiation
17.2 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.8 °C
since 1940
+0.2 °C per decade · r² = 0.29 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
44.7 °C
19 July 1960
Coldest day
-30.2 °C
22 December 1990
Wettest day
35 mm
13 October 1962
Windiest day
42.9 km/h
30 August 1999
Strongest gust
90.7 km/h
4 June 2012
Hottest feels-like
44.4 °C
12 July 2002
Coldest feels-like
-34.9 °C
22 December 1990
Snowiest day
12.0 cm
20 January 1957
Sunniest day
15.0 h
27 June 1940
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 4.9 °C | +1.3 °C | 30 mm | -9 mm |
| Feb | 6.4 °C | -1.5 °C | 75 mm | +43 mm |
| Mar | 15.0 °C | +1.7 °C | 22 mm | -11 mm |
| Apr | 20.1 °C | +1.9 °C | 5 mm | -21 mm |
| May | 25.8 °C | +2.3 °C | 12 mm | -13 mm |
| Jun | 30.7 °C | +2.3 °C | 0 mm | -14 mm |
| Jul | 34.6 °C | +0.4 °C | 7 mm | +3 mm |
| Aug | 33.2 °C | +0.4 °C | 8 mm | +2 mm |
| Sep | 29.4 °C | +2.4 °C | 3 mm | -8 mm |
| Oct | 17.8 °C | -1.3 °C | 41 mm | +20 mm |
| Nov | 13.0 °C | +2.9 °C | 14 mm | -20 mm |
| Dec | 10.0 °C | +5.5 °C | 60 mm | +19 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Caldwell?
Caldwell has a cold semi-arid climate (Köppen BSk). Over 1940-2025, the average annual temperature is 12.2 °C and it receives 285 mm of precipitation per year.
What is the hottest day ever recorded in Caldwell?
The hottest day measured in Caldwell between 1940 and 2025 was 19 July 1960, reaching 44.7 °C.
What is the coldest day in Caldwell?
The coldest day measured in Caldwell between 1940 and 2025 was 22 December 1990, at -30.2 °C.
Does it snow in Caldwell?
Yes. Caldwell gets on average 30.7 cm of snow per year and has around 89 frost days.
Has the climate of Caldwell warmed?
Yes: Caldwell warmed by +1.8 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Caldwell?
The wettest day measured in Caldwell between 1940 and 2025 was 13 October 1962, with 35 mm of rain in 24 hours.
What was the windiest day in Caldwell?
The windiest day measured in Caldwell between 1940 and 2025 was 30 August 1999, with winds reaching 42.9 km/h.
What is the warmest month in Caldwell?
The warmest month in Caldwell is July (26.1 °C on average); the coldest is January (-0.5 °C).
How much does it rain in Caldwell?
Caldwell receives on average 285 mm of precipitation per year, spread over about 68 rainy days.
Is it sunny in Caldwell?
Caldwell gets on average 10.4 hours of sunshine per day, roughly 3,796 hours per year over 1940-2025.
What is the biggest single-day snowfall in Caldwell?
The heaviest 24-hour snowfall measured in Caldwell between 1940 and 2025 was 20 January 1957, with 12.0 cm.
Are there tropical nights in Caldwell?
Yes: Caldwell has on average 12 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Caldwell?
In Caldwell, between 1940 and 2025, the highest apparent temperature reached 44.4 °C on 12 July 2002, and the lowest was -34.9 °C on 22 December 1990.
Compare Caldwell with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Caldwell